Hillstream loaches are the daredevils of rivers, but fish lovers call them crazy creatures; do you know why?

It’s because they’re one of the few exciting water dwellers who can manage in fast-moving bodies of water on steep mountains. And this astonishing ability got them this unique name.

Our primary goal is to comprehend the aquarium-friendly species. So, here we will talk about the prominent varieties like the reticulated hillstream loach as well as other popular ones that find space in pet shops.

We aim to provide you with an avid view on the types of this species along with an exemplary care guide. You will also find the details on its characteristics, food choices, tank mates, breeding patterns, and many other facts.

Fact: Almost 202 species are compositely considered under this category.

Species Overview

About Fish
Scientific Name Balitoridae
Nick Names Lizardfish, Flossensaugers
Family Balitoridae
Source South-east Asia
Average Age 9-10 years
Max Length 7-8 cm
Type Freshwater
Color Pattern Greyish-yellow

What are Their Origin and Habitation

Hillstream loaches are locals to almost every southeast nation, and are vividly found in Vietnam. The South China region is the other populous place for them, while the connecting countries have witnessed this species or sub-types in a few of the streams.

They can be found in the high hilly region’s sliding rivers and streams. It is a fact that they don’t dwell in the still waters of lakes or ponds, or even in rivers while in the planes.

Fast moving water is clean in every sense and it suits them more habitually. The rivers Sekong and Mekong hold a large population of these species.

Xi Jiang, or tributary of Pearl River in China, owns a unique variety of these loaches, which are also named after the country.

Types of Hillstream Loaches

These species are subdivided into multiple categories that have slight differences in skin shades and body shape. Aquarists show interest towards a few of them to get them home.

  • Reticulated Hillstream Loach

These are among the common types in this family. They are seen in most of the loach tanks across the world. Their scientific name for recognition is Sewellia Lineolata, while they are also called tiger hillstream loaches.

Appearance: Their look seems like a floating weapon with a conic tail and wide and round head. These species have large fanned out dorsal fins, almost semi-circle in shape.

The most exciting part is their skin color. There is a tigerish pattern of black spots throughout their bodies, with a few specific designs over the fins or darkish edges.

Often the eyes create an illusion to mix with the spots and fake the predators. The base coloris usually dark yellow or light brown.

A full-grown reticulated species can reach up to three inches, while on average they are no more than two inches.

  • Butterfly Hillstream Loach:

These are officially identified as Beaufortia Kweichowensis, and they are also known as Chinese suckers, which is obviously their source location, China.

Appearance: These species are slightly smaller in size,with 2.5 inches as their maximum achievable length. The body is flattened with theaverage length of the dorsal fins, while the spots are designed in a similar pattern as other loaches.

See also  How Big Do Tiger Barbs Get? What Tank Size Do They Need

The skin color of these species is changeable to match with the background and fake the predators. Mostly they are seen in light yellow or yellowish-brown shade.

Fact: The butterfly hillstream loach is considered as the most beautiful of them all.

How Long do They Live

One fact that makes them worth petting is their durability of many years. The hillstream loach, if well cared for in the tank can live up to ten years, and is therefore valuable.

However, their average life is only about 7-8 years, but they are a bit hard to keep in captivity and may live for fewer years if care is not taken correctly.

Differentiating Male vs. Female Fish

It isn’t challenging to find the gendering difference in the hillstream loach. However, you need to properly analyze them to be very sure about which one is male and which is female. This is especially necessary if you plan to breed them in aquariums.

A male loach is thinner or sleeker in shape with a nicely shaped head. Females, on the other hand, have a thick and wide body with a large head portion.

Another difference is with the pectoral fins because the males have irregular imprints over them near the head, while females do not have any such designs.

Availability and Price

There is no real concern about the availability of these fish, as the whole of Southeast Asia habitats a large variety of them.

But because they are directly caught from the wild (since, it is hard to breed them in captivity), the IUCN Red list has declared them vulnerable to extinction.

The problem that the pet store faces is with shipping them to the destination. Many times they are received by the buyer in deceased form. This is because the hillstream loach finds it difficult to travel in a confined state.

This is one of the primary reasons for them to be sold at a higher price. The average selling price of these species is between $15 to $20.

Fact: About 41,000 thousand species of hillstream loach are under threat to extinction, which is almost 28% of the recognized species till date.

Fish Care

Quick Care Points
Care Level Difficult
Social Friendly
Temperament Peaceful
Diet Omnivore
Breeding Complex

What do They Like to eat?

Their diet mainly consists of omnivorous food habits when they are in wild waters. The hillstream loaches mostly prefer to scavenge for benthic algae formation and crustaceans, which is readily available to them over the rocks under the water.

In captivity these species always trouble the keeper by dejecting to eat commercial food. Many experts even advise to grow the algae naturally in a separate tank to fulfil the food requirements of the loaches.

You can prepare algae in a different container. Put some rock pieces into it and fill the water. Use bright light on a fixed schedule if sunlight is not available, and fertilizers or airstones will catalyze the process. The algae may appear in a week’s time.

 Here are some suggestive food items for these species.

  • Algae
  • Flakes
  • Pellets
  • Wafers
  • Spirulina
  • Vegetables such as zucchini, spinach, cucumber, etc
  • Bloodworms (frozen or live)
  • Daphnia (frozen or live)
  • Crustaceans
  • Brine shrimp

Their Social Behavior

The pet owners refer to them as friendly fish in the aquarium, but they are slightly different. Hillstream Loaches do not bother other aquatics in the tank or surrounding.

These species are one of a kind that mind their own business, which is to keep on looking for food, i.e., algae around the rocks.

However, sometimes they used to feel offended by other fish in the tank. They start behaving aggressively with them to claim their territory. But this is a rare pattern to experience, if the fish gets sufficient space to live.

See also  Bolivian Ram Care: Detailed Guide to Follow

How do They Reproduce

Although, there aren’t any arrangement difficulties in breeding the hillstream loach in captivity,the problem is with the least available research on this subject.

The experts are still unable to deduce the reason why they do not always mate and reproduce, in spite of favorable conditions. You must read the given procedure carefully to breed them successfully in tanks.


It is always recommended to get a separate container for creating an artificial environment that provokes mating in these species.

Maintain the water parameters similar to the main tank, and put sand at the bottom as substrate.


After completing the required settings, you can induce a pair of male and female hillstreamloaches into the tank. Provide them with their favorite food, algae.

You have to follow this for a few days until the male gets aroused and starts seducing the female with its peculiar movements.

The female accepts the offer and comes closer to the partner and mates with them. Now the male fish starts digging holes in the substrate with its tail where the eggs are spawned.

Fact: The eggs of hillstream loaches are less than 2mm in diameter.


The female fish lays its egg in the hole, and the couple waits, loitering around it for about 10-15 days until the eggs hatch. The juveniles are too tiny,but the parents take care of them.

Author’s Note: You can feed the babies with a powdered form of flakes, vinegar eels, brine shrimps, or micro worms for quick growth and a higher chance of survival.

Health Problems Faced by Them

It is understood by nowthough the hillstream loaches look beautiful in fish tanks, they are hard to keep by in-experienced hobbyists.

These species do not have scales on their body, which is known to protect the fishes from local infections.

This is the primary factor that troubles the keepers, because these fish easily catch infections, which can be dangerous from a health point of view.

It is best to maintain hygienic water conditions with optimum water parameters in the tank. Offer them suitable food, and ensure to quarantine the mates before introducing them. Maintain a stress-free environment.

Note: Even medications do not always suit them for the treatment of disease, and they may attain other significant issues.

Tank Care & Regulation

Capacity 200 Litres
Water Temperature 68 to 74 F
Water Hardness 4 to 11 dGH
Tank Lighting Bright 
Water pH Level 6.5 to 7.5
Substrate Rocks, stones, sand
Brackish No

Tank Size Required

These species are pretty small in size and it seems as if they can survive well in 10-20 gallons aquarium. But on the contrary, the hillstream loach requires bigger space to thrive.

A 15-20 gallons tank is good for these species, only if there is just one fish in the tank. The issue is with their schooling habit, as they always stay in a group of 4-5 species.

Lesser in number will increase their stress, which ultimately leads to their death. Therefore, it is essential to pet the group in a minimum of 50-55 gallons tank size.

Find out more about Tank size required for Green Terror Cichlids

Tank Setup

These fish are susceptible to the surroundings where it is kept. Providing them a space that mimics a natural outlook will keep them healthy, calm, and peaceful. Go through the following list of aquarium accessories.


Plants are not among the compulsive items, but experts always suggest having natural greens in their tank. These are always an add-on to the tank while they also serve as a hiding place for the tiny organisms. A few examples are Anubias, java fern, or bucephalandra.

See also  Red Claw Crab: The Eight-Legged Beauty in Your Tank


It is a must to have strong and vibrant lights in the aquarium. Their preferred diet is full of algae, which grows faster in bright light. So, you can use high-beam LEDs in the tank too, which will comfort them while also enabling quick growth of plants and algae formation.


The hillstream loach can settle down well in any type of substrate. So, you can create a nice backdrop with soft mud or thick sand as the base, and a few rock stones with soft gravels at random places.

A piece of driftwood will also appear good while helping as a hiding place for the fish. All these objects conversely help in algal growth naturally.


Now, this is a crucial part as it is unavoidable to get a properly aerated water with high flow in the tank. So, a nice filter system needs to be installed, which perfectly performs the required duties.

A high-power filter will enhance the oxygen level in the water while keeping it clean and safe for the fish. You can use external canisters too.


Decorative pieces are not essential for these species as they are always busy scavenging for algae over the substrate. If you already have some aquarium toys or decors, then clean them properly and then only introduce them into the tank.

Water Parameters

Hillstream loaches are freshwater species that love to swim and stay in shallow waters that are fast moving. The water is mostly clean due to its velocity and holds plenty of oxygen in it.

While caring for these fish in the home aquarium, you can follow the instructions to maintain the water parameters that are suitable for them.

  • The preferred water temperature is between 20 and 23.8 degrees Celsius.
  • The pH levels should be maintained between 6.5-7.5.
  • Use the best quality filters to maintain cleanliness and water currents.
  • Keep replacing the tank water with 50% once a week.
  • High oxygen levels are good for them.

Their Compatible Tank Mates

These are among the mostsuitable community fish and have rarely posed any trouble to their tank mates. Here,the fundamental necessity is to bring them in a group of 5-6 since they love to shoal around.

Whatever companions you bring-in for hillstream loaches should be simple and friendly in nature, and must be able to live comfortably in slightly cold water conditions.

Check out the list of suitable tank mates for them.

Frequently Asked Questions

Do they need water heaters?

These species naturally prefer slightly cold water,around 20-21 degrees Celsius. So, heaters are not really needed.

But if you live in a cooler place where the temperature can drop below this level,then you surely need to install a water heater to keep the place warm.

Do they eat snails or shrimps?

Snails are slow movers and can be easily hunted by the hillstream loaches,but because their mouth is too small, they primarily feed on algae or microorganisms. The same is the case with bigger shrimps; However, they can easily consume brine shrimps.

Are they nocturnal?

The question arises because it is observed that most of the loaches are nocturnal or come out at night. However, the hillstream loaches are completely different, i.e., diurnal, which means they are active during the day time.

Final Thought: Should You get Them Home

These species are becoming a prominent choice of fish enthusiasts because of its unique shape and appearance that makes the aquarium look dazzling.

But despite their attractive looks,there are several issues that need to be addressed alongside them, including a low survival rate on long shipment days, which makes them expensive, and maintaining strict criteria for cleanliness.

It is best to leave them to those who are not beginners, and can afford a group of 4-6 such species in a tank. They always make an excellent addition to the peaceful tank mates.

About the Author

Shelby Crosby

Shelby is a passionate fishkeeper who has been writing about fish for over 5 years. She is a pro aquarist and holds a BSc Honors Degree in Wildlife and Fisheries. She creates her own beautiful aquarium layouts and loves to share her knowledge of tropical fish with other hobbyists.

Career Highlights:

  • Has worked with several aquarium manufacturers as a consultant
  • Organized and hosted workshops on freshwater fish keeping at retail stores, educational facilities, and libraries
  • Released content for the amphibian community through her writings

Educational Highlights:

  • BSc Honors in Wildlife and Fisheries in 2011 (University of Northern British Columbia)
  • Completed her undergraduate thesis on the effects of zoochlorella supplementation on the growth and health of fish.

Writing Experience

Miss Crosby is a Freelance blogger; many of her articles are posted online on various blogs. She has also written a few short articles for "Tropical Fish Hobbyist Magazine" in the past. She is a regular contributor to FishParenting.com. Her education, first-hand experience with fishkeeping, and in-depth knowledge in aquaculture make her one of the most competent writers in the industry.

View All Articles